Let's start with this paper sketch I made. I didn't really bother to draw smooth lines, since Illustrator will do that for me.
Step 1
Import the sketch into a new document. Select it, go to Window >
Transparency (CTRL+SHIFT+F10) and set Opacity to 55%.
Click the square near the "eye" in the Layers palette (F7) to lock the
layer.
Step 2
Create seven new layers and name them: "body", "hands", "mouth",
"eye", "hair", "blush", "clothing".
We will create each element of the girl on a different layer, so we
will be able to edit them easily later on or move them around quickly.
Step 3
Select the "body" layer and lock the other layers. Grab the Pen Tool
(P), remove Stroke and trace the body. Use a purple color.
When you're done, lock the layer and select the "hands" layer.
Step 4
Repeat Step 3 until all elements are drawn. Feel free to set them to any colors you like. This is how mine looks.
Step 5
Now it's time for some shading and details. Select the "body" layer
and unlock it. Grab the Ellipse Tool (L) and draw random circles of
different sizes on the body.
Make them a darker purple than the body. Select all circles and go to
Object > Group (CTRL+G).
Step 6
Grab the Selection Tool (V), select the body and copy it (CTRL+C) and paste it to front (CTRL+F).
Step 7
Remove its Fill and press CTRL+SHIFT+] to bring it to front. Hold
SHIFT key, select the circles created in Step 6 and right-click >
Make Clipping Mask.
Step 8
Lock the "body" layer again and unlock the "hands" layer. Grab the
Pen Tool (P) and draw some simple shades. Make sure you draw them in a
different color.
Step 9
Repeat StepS 5-7 to create clipping masks for the shades.
Step 10
Unlock the "hands" layer and select the shades. Toggle the
Gradients,Color and Swatches windows (Window > Gradients, Color,
Swatches).
Step 11
Select the body and click-drag its color into the Swatches palette.
Then select the shadow, click the Gradient button and replace both
colors of the gradient with the body color from the Swatches palette.
Step 12
Click the second color in the gradient and move the "K" cursor to
the right in the Color palette.
Step 13
Grab the Gradient Tool (G) and click drag like in the image below.
Step 14
Lock the "hands" layer. Repeat StepS 10-14 for the rest of the
parts: hair, dress and shirt.
Done!
You shouldn't worry about getting the colors right, you can always edit them later. Here are some variations I tried.
